SOUTHERN CALIFORNIA SEISMOGRAPHIC NETWORK A Cooperative Project of Caltech and the U.S. Geological Survey April 20, 1995 Weekly Earthquake Report for Southern California ------------------------------------------------ April 13 - 19, 1995 Prepared by: Kate Hutton, Seismological Laboratory (kate@bombay.gps.caltech.edu) Lucy Jones, U.S. Geological Survey California Institute of Technology For further information, please contact the authors or the Caltech Public Relations Office at 818-395-6326. For daily updates, call our Earthquake Information Hotline: 818-395-6977. -------------------------------- This week's Report covers the time period from midnight Thursday morning, April 13, Pacific Daylight Time, to midnight Wednesday night, April 19, 1995, Pacific Daylight Time. We recorded 270 earthquakes of M1.0 or larger during the 7-day period covered. We had another relatively quiet week. The largest quake was a M3.4 Northridge aftershock on Saturday afternoon, which was fairly widely felt in the San Fernando Valley. There was another Northridge aftershock, this time only M2.5, on Monday afternoon. Like almost all of the Northridge aftershocks, the M3.4 was a west-northwest-striking thrust. A M2.7 Landers aftershock was felt in Yucca Valley on Friday evening. Just before noon of Friday, there was a M3.0 near Big Bear, which was an aftershock in the Landers/Big Bear sequence. For some reason, we didn't get any inquiries about it, although it could easily have been felt. That's about all the (seismic) news that's fit to print. The table lists the quakes this week that were M2.0 or larger in the central part of the coverage area. Times are local times; if you want Greenwich Mean Time, add 7 hrs to the Pacific Daylight Time or 8 hrs to the Pacific Standard Time listed. Table 1 ------- Date Time N Lat. W Long. Mag ------------------------------------------------------------- 4/13 12:04 am 35 18.2 118 30.8 2.2 12 mi. NNW of Tehachapi 4/13 12:04 am 35 18.3 118 30.9 2.2 " 4/13 1:30 am 33 57.0 116 24.2 2.1 5 mi. E of Desert Hot Springs 4/13 6:26 am 35 34.5 119 45.3 3.0 20 mi. NE of Simmler 4/13 9:48 am 34 17.0 118 31.7 2.0 3 mi. N of Northridge 4/13 10:12 am 35 0.6 116 58.6 2.3 8 mi. NNE of Barstow 4/13 3:53 pm 33 59.8 118 55.3 2.1 3 mi. SSE of Leo Carrillo State Beach 4/13 5:07 pm 35 5.4 119 7.6 2.4 Wheeler Ridge, 10 mi. WNW of the I5/99 interchange 4/13 5:07 pm 35 4.2 119 7.2 2.5 " 4/13 5:30 pm 35 5.2 119 7.9 2.2 " 4/13 5:34 pm 34 18.3 119 54.0 2.0 7 mi. SSW of Isla Vista 4/13 9:57 pm 36 13.3 120 17.0 2.5 7 mi. NE of Coalinga 4/14 1:28 am 35 57.5 118 18.0 2.5 20 mi. WSW of Coso Junction 4/14 1:49 am 35 55.9 117 39.8 2.3 Coso Range, 17 mi. ESE of Coso Junction 4/14 11:28 am 34 13.7 116 45.8 3.0 5 mi. ESE of Big Bear City 4/14 3:03 pm 34 10.8 116 25.8 2.0 4 mi. N of Yucca Valley 4/14 4:33 pm 33 41.5 116 42.2 2.6 3 mi. S of Idyllwild 4/14 7:09 pm 34 20.1 116 27.9 2.7 14 mi. N of Yucca Valley FELT 4/15 1:19 am 36 30.4 117 54.9 2.0 10 mi. SE of Lone Pine 4/15 8:52 am 33 18.3 117 40.7 2.5 8 mi. SSW of San Clemente 4/15 2:30 pm 34 21.8 116 27.4 2.1 16 mi. N of Yucca Valley 4/15 3:00 pm 34 19.4 118 31.9 3.4 3 mi. S of Newhall; FELT 4/15 11:07 pm 33 43.7 118 40.1 2.3 14 mi. WSW of Palos Verdes Point 4/16 12:28 am 35 1.9 117 0.1 2.3 10 mi. N of Barstow 4/16 3:03 pm 32 2.3 116 23.0 3.1 53 mi. SSW of Ocotillo 4/16 4:59 pm 35 50.6 117 43.5 2.3 15 mi. NNW of Ridgecrest 4/16 11:02 pm 35 52.8 117 54.3 2.0 Coso Range, 11 mi. SSE of Coso Junction 4/17 8:23 am 34 17.8 118 27.9 2.3 1 mi. WNW of San Fernando 4/17 10:19 am 33 43.0 116 50.6 2.1 7 mi. ESE of Hemet 4/17 10:22 am 34 14.1 117 59.1 2.1 4 mi. E of Mt. Wilson Observatory 4/17 3:09 pm 34 17.6 118 23.9 2.5 2 mi. ENE of San Fernando FELT 4/17 9:09 pm 34 25.4 117 43.8 2.4 7 mi. NW of Wrightwood 4/17 9:37 pm 33 23.4 116 23.1 2.4 9 mi. N of Borrego Springs 4/18 5:00 am 34 15.9 118 27.0 2.1 1 mi. SSW of San Fernando 4/18 7:24 am 33 49.5 117 4.9 2.4 8 mi. NW of Hemet 4/18 8:03 pm 33 52.7 116 53.6 2.0 3 mi. SSW of Banning 4/19 2:52 am 35 2.1 116 60.0 2.3 10 mi. N of Barstow 4/19 4:06 pm 35 18.3 118 35.4 2.1 14 mi. NNW of Tehachapi -------------------------------------------------------------